GB1480982A - Electronic flashlight apparatus with automatic light control - Google Patents

Electronic flashlight apparatus with automatic light control

Info

Publication number
GB1480982A
GB1480982A GB3833075A GB3833075A GB1480982A GB 1480982 A GB1480982 A GB 1480982A GB 3833075 A GB3833075 A GB 3833075A GB 3833075 A GB3833075 A GB 3833075A GB 1480982 A GB1480982 A GB 1480982A
Authority
GB
United Kingdom
Prior art keywords
capacitor
thyristor
meter
flash tube
light
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
GB3833075A
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Individual
Original Assignee
Individual
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Individual filed Critical Individual
Publication of GB1480982A publication Critical patent/GB1480982A/en
Expired legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B41/00—Circuit arrangements or apparatus for igniting or operating discharge lamps
    • H05B41/14—Circuit arrangements
    • H05B41/30—Circuit arrangements in which the lamp is fed by pulses, e.g. flash lamp
    • H05B41/32—Circuit arrangements in which the lamp is fed by pulses, e.g. flash lamp for single flash operation

Landscapes

  • Stroboscope Apparatuses (AREA)
  • Discharge-Lamp Control Circuits And Pulse- Feed Circuits (AREA)

Abstract

1480982 Electronic flash apparatus P METZ 18 Sept 1975 [28 Sept 1974] 38330/75 Heading G2X An electronic flash apparatus comprises a storage capacitor C1 dischargeable through a flash tube R÷l, with a series-connected thyristor Ty 1, and a quenching capacitor C2 for applying a blocking potential to the thyristor when a pre-set exposure is reached, a light-emitting diode D 1 being arranged in the charging path of the quenching capacitor. Both capacitors C1 and C2 are charged when a power source (not shown), is switched on. When the camera shutter is actuated, a synchronizing contact SK is closed and a pulse is applied from a triggering device Z to the gate of thyristor Ty 1 and also to the trigger electrode of the flash tube. This discharges capacitor C1 through the flash tube. Light reflected from the photographed object is measured by a light meter LM, and when a pre-set value has been registered (i.e. correct exposure), a pulse is applied by the meter to a second thyristor Ty2. This produces a negative voltage step on capacitor C2, which acts on thyristor Ty 1 to interrupt the discharge circuit. Capacitor C2 is now discharged by the current from capacitor Cl and is recharged in the original sense. Diode D1 lights up during this recharging process, so indicating that the meter LM has responded and operated thyristor Ty2. Some details of circuit modifications are given in Figs. 2-4 (not shown).
GB3833075A 1974-09-28 1975-09-18 Electronic flashlight apparatus with automatic light control Expired GB1480982A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE19742446453 DE2446453C2 (en) 1974-09-28 1974-09-28 Electronic flash unit with automatic light metering

Publications (1)

Publication Number Publication Date
GB1480982A true GB1480982A (en) 1977-07-27

Family

ID=5927028

Family Applications (1)

Application Number Title Priority Date Filing Date
GB3833075A Expired GB1480982A (en) 1974-09-28 1975-09-18 Electronic flashlight apparatus with automatic light control

Country Status (3)

Country Link
JP (1) JPS5161827A (en)
DE (1) DE2446453C2 (en)
GB (1) GB1480982A (en)

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3993929A (en) * 1975-12-19 1976-11-23 Honeywell Inc. Automatic correct exposure indicator
US4193677A (en) * 1977-07-29 1980-03-18 Nippon Kogaku K.K. Warning circuit in an auto-controlled flashlight photographing device
JPS5661797A (en) * 1979-10-26 1981-05-27 Fuji Photo Optical Co Ltd Automatic strobe dimming system and device
DE3637645C3 (en) * 1986-11-05 1997-06-05 Studiotechnik W Hensel Gmbh & Flash unit for photographic purposes, in particular flash lamp and generator for studio and outdoor recordings

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1940383C3 (en) * 1969-08-08 1975-04-30 Metz Apparatewerke, Inh. Paul Metz, 8510 Fuerth Electronic flash unit with automatic light control
DE2152140C2 (en) * 1971-10-20 1973-11-29 Metz Apparatewerke, Inh. Paul Metz, 8510 Fuerth Electronic flash unit with automatic light control
JPS519819A (en) * 1975-05-20 1976-01-26 West Electric Co JIDODENSHISENKOSOCHI

Also Published As

Publication number Publication date
DE2446453C2 (en) 1983-05-11
DE2446453B1 (en) 1975-07-10
JPS5161827A (en) 1976-05-28

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Legal Events

Date Code Title Description
PS Patent sealed
PCNP Patent ceased through non-payment of renewal fee